Distillation of water



y 12, 1932- G. E. HUGHES ET AL 1,867,075 I DI STILLATION OF WATER FiledFeb. 15, 1950 2 Sheets-Sheet 1 July 12, 1932.

G. E. HUGHES ET AL.

DISTILLATION OF WATER 2 Sheets-sheaf, 2

Filed Feb. 13. 1950 FLHSH Bonn:

FLHSH 50mm.

1-1 QSH Bowen.

DE-HERATOR PUMP l atented July 12, 1932 T775511? UNITED STATES PATENT IGUY ERSKINE HUGHES, ALFRED HAROLD WA EI G AND :roII'Nv EDGAR BEAI AM, oNOR-"P 'roN-oN-rEEs, ENGLAND, AssIGNoEs T0 IMPERIAL CHEMICAL INDUSTRIESDIM-i ITED, 0E LoN oN, ENGLAND, A BRITISH ooMrANY 1 v DISTILLA'IION orWATER" Application filed February 13, 1930, Serial No. 428,120, andGreat BritainFebruary14,1119i-J ing a freely falling film of liquid to asource of heat and optionally condensing the vapours by means of asimilar film of liquid and We have now found that this process ispeculiarly well applicable to the production of distilled water,especially when a multiple stage evaporation process is employed, ashereinafter described. I

The apparatus for carrying out the present process, which will now bedescribed, consists, in so far as it is novel of several identicalunits.

Each unit comprises a plurality of straight v v should produce in threestage evaporator, j

vertical tubes, mounted between end plates ina casing. Just below theupper end plate;

each tube is provided with a liquid supply (which may consist of asiphon pipe attached to a common supply tank) and a liquid dis tributorto distribute the liquid around the tube. 1

The liquid which remains un-evaporated after circulating down theoutside of the tubes may be collected on the lower end plate andreturned, by means of a pump to the liquid distributors.

The process will now be described for simplicitys sake in itsapplication to athree stage distillation plant, though as a matter offact, in actual practice as many as seven or eight stages may beemployed. The raw water is pumped through a deaerator'and heater (whichis heated as subsequently explained, by part of the steam produced inthe second stage) into a commonraw water supply main connected to allthree stages of the distilling plant.

From this it passes to the evaporators p 7 Water supplied by pipe 25 iscirculated by pump 10 from the bottom (above the tube which are the sameas above described.

The first evaporator is fed with steam from an external source. This iscondensed by indirect contact with the raw water, and passes, through aflash-boiler to the common distilled water main.

The purpose of the flash boiler is to collect the steam evolved duringthe releasefoffpres-j' sure on the water which accompanies it'sj'passage into the distilled waterl il'a i lil j 5 f The steam evolved intheflash boiler passes, along withthe steam evolved duringthefirst stage,into the second stage evaporator. f

Here it serves to evaporate a further'quan-' tity of hot raw water andisitselifcondensed and flowsinto the distilledwater 'mainQ- The stearn'from, the second stage evaporatoijisiin part used to preheatf the'entering water', passes to the distilled condensed thereby, and watermain. V Y

The steam from'th'e'third stage evaporator is led off to a condenser,supplied with water from an external source. The wholeofthe distilledwater is 't l en; an ex traction pump.

vTheoretically a given weightiof stea-ni nearly four times its weight oftotal distilled 'evaporators, as a certain amountof blowing down isneeded to keep the tubes of the evap- V orator clean.

Instead of steam the heating agent for the first stage, may be gases ofcombustion.

The invention is illustrated in the accom panying drawings. 7

Figure 1 is a sectional elevation of a single 7 unit.

Figure 2 a plan on the line A' A of Fig plate l) of 1 up through pipe 11and into supply tank 7 from which it passes through Y siphon pipe 8 tothe external distributors9 and so down the outside of the tubes. Steam rpasses 0E at 2 1 and distilled water at 11.

InFigure 3 the course of the raw water is 7 shown by dotted lines, thecourse taken by the distilled water by thin full lines, that taken bythe condensing water by thick full lines and that of the steam by doublelines. The pumps lO and the details ofthe evaporators are not shown. 2

The plant consists of three evaporators 124113 14,, a condenser 15, adetaerator and i '1 1 6; an, extraction pump 17 and boilers 18, 19, 20.

. 21 22, 23 are'blow-down lines.

We declare that what we claim is r 1. An apparatus for the distillationof Wa 15 ter comprising a plurality of"evaporators," connected. inseries and in multiple effect, a v plurality oi mainfsteam pipes betweensuccessive effects, a plurality of flash boilers each u adaptedto-receiv'e condensate from a sepa- 7 39 rate eflectgandgeach having asteam pipe join: 7

ing. the; main" steam pipe between successive 'efl'ects, alcondensedwater main connecting all of said flash boilers and an extractionpumpjofi said condensed water main;

7 g 2. An apparatusfas set forth in claim 1 whichi-the e'vaporators arevertical film evap craters. t a I or 3; An apparatus asset forth inclaim 1, 2 comprising in addition a de-aerator. con- :0 nected to themainsteam pipe of the penulti mate efiect. 1 In; witness whereof; Wehave hereunto ibgz'grbed our names this 30th day of January, 55, ERSKINEHUGHES; a I ALFRED HAROLD WARING. V .JOHNQEDGAR 'BRAHAM. li'

